1. Field of the Invention
The present invention relates to the field of semiconductor packaging, and more specifically, to a semiconductor package which inputs a first power supply voltage from a mother board and converts the voltage into a second voltage which is used to power a semiconductor integrated circuit contained therein.
2. Description of Relevant Art
Integrated circuit packages come in a wide variety of shapes, sizes, and materials depending upon on the interconnection requirements of the specific circuit and system. The main function of integrated circuit packages is to provide for electrical connection of an integrated circuit to a printed circuit board, and to provide protection for the integrated circuit. Modern packages for the latest high density integrated circuits are very sophisticated and can contain up to several hundred leads or pins. The leads or pins provide means for supplying power and ground supplies to a chip contained in the package and for inputting and outputting signals representing data, addresses, and other information to and from the chip. Modern high density integrated circuits such as microprocessors and math co-processor chips are typically contained in ceramic pin grid arrays or multi-layer molded plastic packages.
Presently most integrated circuits operate at 5 volts V.sub.CC. Present packages input 5 volts V.sub.CC from a power supply located on a circuit board and distribute this operating voltage to vadous locations on the chip. As integrated circuit fabrication techniques become more advanced, transistor dimensions are decreasing allowing for higher density and more complex circuits to be manufactured. These modern integrated circuits, however, will require a lower operating voltage of approximately 3.3 volts V.sub.CC instead of 5 volts V.sub.CC, in order to prevent device failure or breakdowns. The lower operating voltage is also useful because less power is consumed by the integrated circuit. Future integrated circuits will be fabricated with 3.3 volt or lower processes as opposed to 5 volt processes.
Not only will future devices operate at approximately 3.3 volts V.sub.CC, but present integrated circuits which now operate at 5 volts V.sub.CC will also eventually be made to operate at 3.3 volt V.sub.CC. That is, for example, a present Intel.RTM. 386 microprocessor which now operates at 5 volts V.sub.CC will eventually be fabricated with a process wherein it will operate at 3.3 volts V.sub.CC and not 5 volts V.sub.CC. Present devices now fabricated with 5 volt processes will be fabricated with 3.3 volt processes because it is too expensive and difficult to run two different fabrication processes at a single facility. Moreover, a device made from a 3.3 volt fabrication process will eventually be cheaper to manufacture than a device made from a 5 volt fabrication process.
Unfortunately, however, there are many computer systems which are designed around chips that require 5 volts V.sub.CC. These systems run the risk of becoming obsolete since they provide 5 volts V.sub.CC to the package containing the chip while eventually only chips which operate at 3.3 volts V.sub.CC will be available. A chip failure will result in the entire system becoming obsolete because these systems will not be able to obtain replacement chips which are compatible with their 5 volt electrical power distribution design.
Thus what is needed is an integrated circuit package which can receive 5 volts V.sub.CC from a circuit board but yet provide approximately 3.3 volts V.sub.CC to the integrated circuit contained therein.